Traditional approaches to radio communications in specific frequency bands of the RF spectrum have typically involved designing a radio to work only in that band. That is, traditional radios are designed with band specific filtering and hardware, which ensure reliable and robust communication in that specific frequency band, but preclude the radios from being used in any other frequency bands of the RF spectrum.
Modern radio transceiver hardware is capable of operating over a wide range of the RF spectrum with only software-configurable changes. However, to provide reliable and robust communications in a specific frequency band, the wideband radio transceiver hardware is augmented with band-specific filtering hardware. This, however, constrains the radio to operate only in the selected frequency band. In order to support robust communications in multiple frequency bands, traditional wideband radios must include the appropriate circuitry (for example, filters and switches) for each of the multiple frequency bands, despite being able to only use a single frequency selection at any one time. The support for multiple frequency bands typically results in the traditional wideband radio being impractical due to size and switching loss factors. Thus, performance is sacrificed in order to maintain flexibility in traditional wideband radios.
Antennas for communication that interface with these traditional wideband radios must be chosen to be compatible with the selected portion of the RF spectrum, and typically only comprise antenna elements and integrated amplifiers to improve system level noise performance. These radios also support integration with specific-use antennas, such as GPS antennas. Active GPS antennas typically comprise a radiating element, a low-noise amplifier (LNA), and a filter tuned to the frequency characteristics of GPS signals, whereas passive GPS antennas typically comprise only the radiating element. Both active and passive GPS antennas are explicitly designed only to receive GPS signals, and are not designed or enabled to receive other types of signals or transmit any signals.